Original puzzle laboratory

Six ways to think like a casebook

Short, original challenges based on reasoning modes—not copied programme puzzles, props or dialogue.

Last checked 4 October 2026 · Sources & corrections
A puzzle worktable with original blank grid, route sketches and reasoning tools
Original fan artworkUnofficial archive commissionAI-assisted original fan artwork · not programme material
Puzzle laboratory

Reasoning should feel playable

The worktable turns constraints, routes, language and geometry into an inviting place to experiment.

Sequence

Four visits occur at 09:05, 09:20, 09:35 and 09:50. Ada arrives before Ben; Cleo is last; Ben is not second. Who is second?

Hint 1 · Place the fixed visit

Cleo is last, so begin by fixing the fourth position.

Hint 2 · Eliminate the impossible slot

Ben cannot be second, and Ada must appear before Ben.

Hint 3 · Show the reasoning

Ada must be first, Cleo fourth and Ben third, leaving Dara second.

Testimony

Exactly one statement is true. Ada: “Ben did it.” Ben: “Cleo did it.” Cleo: “Ben is lying.” Who is consistent with the rule?

Hint 1 · Test, do not guess

Try each possible culprit and count how many statements become true.

Hint 2 · Protect the rule

The correct candidate must leave exactly one truthful statement.

Hint 3 · Show the reasoning

If Cleo is responsible, Ben’s statement alone is true.

Route

A route must visit Gate before Bridge, and Library immediately after Bridge. Which route works?

Hint 1 · Keep the pair together

Bridge and Library form a two-stop block because Library must immediately follow Bridge.

Hint 2 · Position the gate

The remaining rule places Gate before that two-stop block.

Hint 3 · Show the reasoning

Gate–Bridge–Library satisfies both the ordering and adjacency constraints.

Geometry

A ball travels east, rebounds from a vertical cushion and continues at the equal reflected angle. Which general direction follows?

Hint 1 · Name the surface

A vertical cushion changes the horizontal part of the ball’s motion.

Hint 2 · Preserve the angle

The rebound mirrors the incoming path rather than creating a new angle.

Hint 3 · Show the reasoning

Reflection reverses the horizontal component while preserving the angle.

Language

Which word means both a written account and something to achieve?

Hint 1 · Change grammatical role

Look for one spelling that can work as both a noun and a verb.

Hint 2 · Connect document and achievement

One meaning is an account; the other is something a competitor may set.

Hint 3 · Show the reasoning

“Record” can be a documented account and, as a verb, an achievement to register; the ambiguity is the point of the exercise.

Identity

Two identical folders are swapped. Only one has a torn lower corner. What evidence survives the swap?

Hint 1 · Ignore movable information

Position and label colour can change when the folders are swapped.

Hint 2 · Find the persistent property

Look for evidence physically attached to one folder.

Hint 3 · Show the reasoning

A persistent physical property survives a change of position or label.

All six challenges are original instructional exercises. They demonstrate reasoning habits and do not reveal episode solutions.

Words and puzzles

Read the best short lines in Ludwig, or choose your spoiler boundary and try the fifteen-question Ludwig quiz.

How we check: every fact on this page is taken from the BBC, the production companies or named, dated reports. See our sources and method or send a correction.

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